THE transmission lines, running from Gippsland’s proposed offshore wind energy facilities, will not go underground from Giffard, near Yarram, to the Latrobe Valley.
VicGrid chief executive Alistair Parker has ruled that out as simply too expensive and unsustainable on customers’ electricity bills.
Speaking on ABC Radio on Friday, Mr Parker said it would cost $4.5 billion to put the transmission line underground, as against $1.5 billion to run the line across farmland, on 50 metre to 76 metre-high lattice towers.
“What we find is, if we were to do it underground, it would really increase the cost, it would have a couple of other issues, but really increase the cost of the project.
“We estimate will cost about one and a half billion, but if we were to do it underground it would be four and a half billion. And obviously that goes through the electricity bills, and we've had a lot of feedback, obviously, in the cost of living crisis, that people are more generally worried about electricity in terms of that longer term offshore wind target.”
Mr Parker also revealed a couple of other things about the transmission of power from Gippsland’s offshore wind energy facilities, the first of the transmission lines will be 500kV, not 300kV, and there has been a refinement in the transmission route study area, ruling out Holy Plains Park and an area west of Loy Yang Power Station.
He also revealed that there would ultimately need to be two 500kV transmission lines coming up from an area, 6km in from the coast at Giffard to Loy Yang.
“And probably worth clearing one thing up, the government has a target of 9GW across all of Victoria (from offshore wind), you might expect about 7GW of that to be in Gippsland,” he said, noting the initial 500kW line was on the basis of the 2GW the government wanted first-up from offshore.
“We also did a bit of work just to think what that long term would look like and we believe you would need two lines back to the old transmission system (at Loy Yang). So, you would need two 500kV lines running back to the Latrobe Valley.”
Mr Parker said it wasn’t a matter of dividing 7GW by two and needing 3.5 times the transmission capacity. By operating the two 500kV lines in a loop it created efficiencies capable of handling the ultimate 7GW the government wanted from Gippsland offshore wind.
Background
VicGrid is developing the shared transmission needed to connect offshore wind energy generated off the Gippsland coast to the grid.
In March 2024, they established a study area for the transmission needed to achieve at least 2GW of offshore wind energy by 2032. The study area starts approximately 6km from the coast near Giffard and extends northwest past Stradbroke West to Willung, across to Flynns Creek to the Loy Yang Power Station.
VicGrid has completed desktop analysis and applied the refinement criteria to identify and assess areas suitable for further investigation to host transmission for the first 2GW of offshore wind.
Using these criteria and VicGrid’s guiding principles, the refinement work so far has identified:
- Areas that are not suitable for further investigation and have been removed from the study area
- Areas suitable for further investigation to host transmission infrastructure.
Some areas have been identified as not suitable to host transmission for a range of reasons, including presence of highly sensitive protected species, technical constructability or feasibility.
“After careful consideration of the merits and complexities of 330 kilovolt (kV) and 500kV transmission technology, we decided a 500kV transmission line is the most suitable solution for this project.
500kV transmission has a higher transfer capacity than 330kV transmission technology and will result in around half the power loss of 330kV transmission,” said VicGrid.
“Power losses happen when electricity is transported across a network, and higher power losses increase costs for consumers.
“To achieve future offshore wind energy targets of up to 9 gigawatt (GW), the 500kV solution would require only a single set of towers per corridor. The 330kV solution would require two sets of shorter towers, which would have a higher visual amenity impact.”
New REZ map soon
VicGrid is yet to announce details of any refinement to its renewable energy zone (REZ) study area map, that is areas in Victoria considered of worthy of additional investigation for hosting renewable energy infrastructure including wind turbines, solar panels, batteries, and transmission lines.
Several of these ‘Tier 1’ study areas, viewed as most suitable for renewable energy infrastructure are located in Bass Coast and South Gippsland.
A comprehensive final engagement report including detailed summaries of the study area feedback, and how it will help inform decisions, was to have been published by October 31, 2024.
A spokesperson for VicGrid said last month that, owing to the fact that they had received more than 930 study area feedback responses, the report was taking longer to compile.
“The comprehensive final engagement report including detailed summaries of the study area feedback, and how it will help shape the process to identify draft proposed renewable energy zones, will now be published in December.”
With only a few days left until the Christmas shutdown, we have asked VicGrid to say when the report would be released.
